The two of us have been digging in to reconcile the differences between us for 15 years. What are we digging into? The thick, rich, confusing soil of the different ways we think, experience, and understand the world.

Muhammad has become a strangely unifying figure in America—able to get conservative Glenn Beck and liberal Bill Maher to agree that Islam is a backward, medieval religion and a threat to all civilization. Both are making a common, fundamentalist mistake.